410

ELEMENTS OF MATEIIIA MEDICA.

white, the other yellowish white), to meet the demands of his customers !The yellow tint is owing to the presence of iron, which is readily detectedin the salt by the blue colour immediately produced in its solution byadding first a few drops of dilute sulphuric acid, and then ferrocyanuretof potassium.

Emetic tartar is sometimes adulterated with bitartrate of potash. Ac-cording to Mr. Hennell (Phillips’s Transl. of the Pharm. 3d ed.) the anti-monial salt may contain 10 per cent, of bitartrate, and yet the whole willdissolve in the proper quantity (14 or 15 parts) of water. In order todetect any uncombined bitartrate, he adds a few drops of a solution ofcarbonate of soda to a boiling solution of the antimonial salt, and if theprecipitate formed be not dissolved, he concludes that there is no bitar-trate of potash present. ^

A pure solution of emetic tartar should occasion no precipitate withchloride of barium: it produces a white precipitate (unless the solutionsbe very dilute) wdth nitrate of silver, soluble in excess of water.

Physiological Effects, [a.) On vegetables .—Emetic tartar acts asa poison to plants {vide the experiments of Schiibler and Zeller, inSchweigger's Journ.f.d. Chem. 1827, B. 50, S. 54-66.)

(b.) On animals .—An extended examination of the effects of emetictartar on the different classes of animals is still a desideratum. Hithertoexperiments with it have been principally confined to dogs, rabbits,horses, oxen, sheep, and cats. Moiroud ( Pharm. Veter. 287) has giventwo drachms to horses, and gradually increased the dose to six ounces,without perceiving any remarkable and permanent derangement in theexercise of the principal functions. Gilbert (quoted by Moiroud) hasexhibited ten drachms to a cow and four to a sheep without any remark-able effect: but six drachms killed an animal of the latter species. Ma-gendie (in Orfila’s Toxicol. Gen .) examined its effects on dogs. He foundthat from six to ten grains introduced into the stomach killed the animalsin from two to three hours, when the gullet was tied: those who wereable to get rid of it by vomiting took as much as a drachm without expe-riencing any bad effects, and in some cases half an ounce causedno ill effects. From his experiments it appears to operate locallyand by absorption, its principal action being on the intestinal canal andlungs : for nausea, vomiting, alvine evacuations, difficulty of respiration,and accelerated respiration, were produced by injecting a solution of thesalt into the veins, by introducing it into the stomach, as well as byapplying it in the solid state to the cellular tissue. Traces of pneumonia,gastritis, and enteritis, were found after death. These experiments havebeen repeated by Bayer and Bonnet {Diet, de Med. et de Chir. Prat.iii. 69) on rabbits ; but without obtaining the lesion of the lungs men-tioned by Magendie : in some cases no appreciable lesion was observedin any organ. Dr. Campbell (quoted by Dr. Christison) found no pul-monary inflammation in a cat killed by this salt. According to Flourens {Journ. de Chim. Med. ix. 21) emetic tartar injected into the veins ofruminants causes efforts to vomit, but not actual vomiting; of the fourstomachs possessed by these animals, the reed or true stomach is theonly one affected by it.

(c.) On man. a. Local effects .—Emetic tartar is a powerful local irri-tant, but not a caustic; that is, it does not exercise any known chemicalinfluence over the parts with which it is placed in contact. Its irritant